The aim of this Shared Instrumentation Grant application is the acquisition of an upgrade of a Visual Sonics Vevo(R) 2100, to Vevo(R) LAZR Photo acoustic and Ultrasound Imaging System, allowing for the totally new imaging modality to be made available. This upgrade will have an enormous impact on the many projects, both basic science and translational, across Stanford University's diverse research community. The existing Vevo(R) 2100, a high frequency ultrasound, offers users the ability to view internal anatomical features with high spatial resolution. The proposed upgrade will allow photo acoustic imaging by contributing optical contrast, enabling real-time images possessing anatomical, functional and molecular information, extremely important for better understanding of underlying biology and for successful translational studies. Major research applications of the Vevo(R) photo acoustic technology are envisioned to be in the areas of oncological, cardiovascular and neuro- imaging. This technology allows imaging of both endogenous (hemoglobin, deoxyhemoglobin, melanin) and exogenous contrast agents and molecular probes (single walled carbon nanotubes, gold nanoparticles etc.) and as such will provide for our research community a unique insight into diverse studies, including investigations of the tumor microenvironment, metastases, cerebral and tumor hypoxia, and myocardial strain. In the long run, we believe these studies will have a profound impact on early detection of a range of disorders as well as on the improvement of various areas of patient care such as staging, therapy evaluation and overall patient management. Since clinical photo acoustic systems are under development by several groups, the small animal studies described herein are highly relevant to public health and support not only the biomedical research goals set at Stanford University but align well with NIH's mission of advancing human health through fundamental scientific discoveries. The investigations will take place at interdisciplinary laboratories directd by recognized leaders in biomedical research: multimodality molecular imaging (Dr. Sanjiv Sam Gambhir), molecular imaging probe development (Drs. Jianghong Rao and Zhen Cheng), cardiovascular disease (Drs. Euan Ashley, Joseph Wu and Ching-Pin Chang), and diagnostic radiology (Drs. Juergen Willmann, Amelie Lutz and Aya Kamaya).